1. Field of the Invention
The present invention relates to an image forming apparatus.
2. Description of Related Art
A related art image forming apparatus employing an electrophotographic method has served as, for example, a printer, a photocopier, a facsimile device, and a multi-functional peripheral. In the related art printer, for example, a surface of a photosensitive drum is uniformly charged by a charging roller, and is irradiated with the light by a light emitting diode (LED) head to form an electrostatic latent image thereon. After a development device disposed in the related art printer develops the electrostatic latent image to form a toner image on the photosensitive drum, the toner image is transferred to a sheet by a transfer roller and is fixed onto the sheet by a fixing device.
The development device includes a development roller, a toner supplying roller, and a development blade, and allows toner supplied from a toner cartridge to be charged, so that a thin layer of the toner is uniformly formed on the development roller. Accordingly, a development voltage, a supply voltage, and a regulation voltage are adjusted and respectively applied to the development roller, the toner supplying roller, and development blade. The toner undergoes friction between the development roller and the toner supplying roller, and between the development roller and the development blade (e.g., Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application Publication No. H08-334955
Such a related art printer, however, may cause phenomena such as blur by transfer, fog, smudge, and filming which cause deterioration of image quality in a case where a surface potential of the photosensitive drum and a setting value of the development voltage are not appropriate. The blur by transfer is a phenomenon in which the toner is not sufficiently adhered across an image portion on a sheet in the course of transfer of the toner image to the sheet. The fog is another phenomenon in which a small amount of the toner is adhered across a non-image portion (blank portion), while the smudge is a phenomenon in which the toner is locally adhered to a non-image portion, a half-tone portion and the like in a granular manner, a streak manner, or a band-like manner. The filming is another phenomenon in which a white portion is locally formed in a granular shape, a streak shape, or a band-like shape when a solid image is printed across the sheet.
The present invention is proposed in consideration of the aforementioned situations, and provides an image forming apparatus capable of reducing occurrences of blur by transfer, fog, smudge, filming, and the like, thereby improving image quality.